Bellcrank

Illustration of a bellcrank from the 1908 Chambers's Twentieth Century Dictionary

A bellcrank is a type of crank that changes motion through an angle. The angle can range from 0 to 360 degrees, but 90-degree and 180-degree bellcranks are most common.

The name comes from its first use, changing the vertical pull on a rope to a horizontal pull on the striker of a bell to sound it.